Faculty of Earth Science and Technology, Bandung Institute of Technology Faculty of Engineering and Design, Bandung Institute of Technology and Science PRESENTED IN: Cikapundungriver(28km)holdsaverystrategicroleasoneofthewater supplysourceforBandung,butthewaterqualityisdecreasingoverthe years. This degradation has also influenced the groundwater in its riverbank. INTRODUCTION: The base map was built using a total of 32 scenes of WorldView-2 image, combined with Aster image. The dimension of the model was one layer model with elevation (Z) 400 to 2200 above the sea level, total cell 361 rows and 454 columns, Cellactivated was only 144 km2, as wide as Cikapundung watershed, and the river was set in constant head condition, Two types of rocks were defined based on the existing geological maps: Volcanic breccias with Conductivity=10-6m/detik;Storage=0.02;Specificyield=0.02;Totalporosity=0.5;Effectiveporosity=0.1;Sand and clay intercalations with Conductivity =10-8 m/detik; Storage =3.3e-6; Specific yield =0.08; Total porosity =0.11; Effective porosity =0.1. The parameterization of the stream was divided into two segments (width x depth x hydraulic conductivity): Curug Dago to Viaduct 4.5 m x 1.08 m x e-5 m/sec, Viaduct to Dayeuhkolot 4.4 m x 1.5 m x 5.4e10-5 m/sec. Initial head were observed at: 19 dug wells, 24 river points, and two spring points in 2013. All parameters accommodated by software SWS visual MODFLOW flex 2012, that used three-dimensions mathematic equation to build a conceptual model. The equation in steady state is:DATA AND METHODS: Figure: Conceptual model Cikapundung Watershed Modelhasbeencalibratedandshowedanappropriatenesswith19dug wells and 2 springs with correlation coefficient of 0.92 and water balance in 0.01 steady state condition (2040 m3). Theconceptualmodelsuccessfullyreplicatesthepreviousanalytical modelshowingthreesegmentsofwaterinteractions:noflowatsegment MaribayatoCurugDago),combinationofeffluentandinfluentflowat segment Curug Dago to Viaduct), and influent flow Viaduct to Dayeuhkolot. However, the model shows some local variations that was not spotted in the previous model.CONCLUSIONS: Figure:Results of the finite difference modeling of Cikapundung watershed Figure:Calibration of Head Acknowledgement:Agus M Ramdhan, Ph.D (Head of Groundwater Engineering Progamme) FOR MORE INFORMATION: Dr. Dasapta Erwin Irawan erwin@gc.itb.ac.id Achmad Darul,M.T. darul.gg04@gmail.com Contributors: Ivan Febyanto Wisnu A Pratama Nugraha S Komara Author: Achmad Darul , Dasapta Erwin Irawan, Nurjanna Joko Trilaksono, Ulfi Rizki Fitria, Aditya Pratama This paper discusses our effort to transform analytical research model on hydrodynamic interaction of groundwater-river water in 1997 into numerical model Figure:Calibration of Water Balance RESULT: Yoga Prasetyo Janner R Nababan Agathon C Setiawan CONCEPTUAL MODEL OF GROUNDWATER AND RIVER WATER INTERACTIONS IN CIKAPUNDUNG RIVERBANK, BANDUNG, JAWA BARAT (PENG-07)Figure:Pengukuran muka air sungai pada segmen Dago-Viaduct